Several modes of communication are currently employed to accommodate users/operators who are either hearing impaired (deaf or having a hearing handicap) or speech impaired (having an inability to speak or a speaking handicap). Common modes of communication are voice, TTY, hearing carryover (HCO), and voice carryover (VCO). The voice mode may be utilized for users/operators who are neither hearing impaired nor speech impaired. The TTY mode may be utilized when a user/operator is both hearing impaired and speech impaired. The HCO mode may be utilized when the user/operator is speech impaired but not hearing impaired, and VCO mode may be utilized when a user/operator is hearing impaired but not speech impaired.
In an existing device, when initiating a call from a TTY equipped vehicle, it is assumed that both the vehicle and the call recipient are in TTY mode. There is generally no verification from the call recipient that the call is actually connected or that the communication device has been adapted for communication in TTY mode. In this existing device, a twenty-second call set-up timer may be utilized to allow both the call initiator and the call recipient time to adapt the communication devices to TTY mode after a connection is made. After the twenty-second call set-up time expires, data is transmitted in TTY mode without a connection verification, assuming that the operators have correctly adjusted the mode of their communication devices.
While the above system functions adequately in many instances, it would yet be desirable to provide an improved multi-mode communication system suitable for users/operators with special needs, such as hearing and/or speech impaired users/operators, which may substantially eliminate the need for a call set-up time and may provide verification of connection and mode.